Particle generation of ceramic emitters for cleanroom air ionizers

The ceramic emitter which is composed of a needle-shaped silicon and a silicon carbide ceramic rod was developed for an LSI cleanroom air ionizer. The concentration of the particles generated from the ceramic emitter and the conventional tungsten emitter was measured in an air and an argon atmosphere. The concentration of the generated particles was the lowest for the ceramic emitter operated in the argon atmosphere. It is considered that oxide thin film formed on the emitter plays an important role in the mechanism of the particle generation due to emitter degradation.